Mr J D Tyler of Knowle is on the right track with his query about submerged turbines except that he is referring, not to CMT, but to MCT (Marine Current Turbines), as the company concerned. Three years ago, one of MCT's technical staff came to talk to a meeting of Bristol & S W SERA, the Socialist Environment and Resources Association.

The presentation was well-received, being both stunning and convincing in terms of advantage relative to alternative energy technologies.

Mr Tyler could doubtlessly obtain an updated flavour of that presentation by typing the company name into his search engine.

Bernard J Seward, Secretary Bristol & S W SERA, 164b Wellington Hill West, Bristol.